[roll pigweed] pw_span: Replace pw_polyfill.span deps with pw_span

The pw_polyfill.span library will be removed. Targets should depend
directly on pw_span instead.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/100440

https://pigweed.googlesource.com/pigweed/pigweed
pigweed Rolled-Commits: abe1ca33ea3eae1..63b83f7d3de21b3
Roller-URL: https://ci.chromium.org/b/8809993679466433905
Cq-Cl-Tag: roller-builder:pigweed-zephyr-roller
Cq-Cl-Tag: roller-bid:8809993679466433905
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I0bb441e8e17f12b871b0eac2c957503462adc775
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/zephyr-integration/+/100408
Bot-Commit: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
Commit-Queue: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/pigweed b/pigweed
index abe1ca3..63b83f7 160000
--- a/pigweed
+++ b/pigweed
@@ -1 +1 @@
-Subproject commit abe1ca33ea3eae14a26a0ba7c95f13316b874062
+Subproject commit 63b83f7d3de21b3905a41065b912316d68d53c4d